GLACIAL GRAVEL IN LIMESTONE, RIPON, WISCONSIN 63 
by glacial pressure, as one would buckle a sheet of paper by pushing 
slightly on one side, the explanation is perfectly adequate. It is 
not even necessary to assume a glacial origin for the fold, for 
Fic. 6.—Gravel seam in west face of quarry, showing joints 
pressure with the beds in their present position would account for 
the phenomenon. The filling can be ascribed either to glacial or 
to post-glacial waters, under this view. 
